1. Field of the Invention
The present invention relates to a history adding device that generate a history-added image file and an electronic camera. The present invention also relates to an image processing program for processing the history-added image file.
2. Description of the Related Art
In a conventional electronic camera, image processing such as color interpolation, color correction, noise filtering, and edge enhancement is applied to image data. A processed image thus generated is highly versatile and convenient for a user because it is easily opened by general image display software for printing.
Also, there is another known electronic camera that generates a RAW image approximate to an image outputted from an image sensor. A user can apply advanced image processing to this RAW image later (ex-post determination of image quality). A user can also create images later according to his/her intended uses, for example, creating from one RAW image an image suitable for high-definition printing as well as a small image suitable for electronic mail enclosure (for multiple purposes). In addition, storing an image in a RAW image form makes it possible to apply a future-available advanced image processing thereto. Accordingly, images of better quality than that of images obtained at the time of shooting will be obtainable in the future (the application of the latest technology).
As described above, the processed image is advantageous in its usability, while the RAW image is advantageous in the ex-post applicability of advanced image processing.
There is a known electronic camera that selects one of the processed image and RAW image to record the selected image (for example, disclosed in Japanese Unexamined Patent Application Publication No. 2001-61067). Also, another known electronic camera generates both the RAW image and the processed image at each shooting and records them independently (for example, simultaneous recording of RW+JPEG).
However, there are some cases where additional image processing is performed on a completed processed image later, for example, where a user later adjusts image quality of the processed image as desired, or an output device such as a printer automatically makes additional adjustment to image quality of the processed image in order to optimize it for output. Such additional image processing causes degradation in image quality, for example, as follows.